多层螺旋CT锥形线束校正重建技术:适应性倾斜多层平面重建法

多层螺旋CT的应用可以大大提高扫描速度、图像分辨率和球管输出毫安的利用率.不同的图像重建技术直接影响螺旋CT的图像质量.本文介绍单层、4层、和16层螺旋CT不同的重建技术的不同特点.由于扇形CT(第三代CT原理)的锥形线束的几何原理,8层和8层以上的多层扫描,如果没有特殊的锥形线束校正重建,严重的锥形束伪影明显影响图像质量.采用适应性倾斜多层平面重建AMPR技术,锥形束伪影得以有效消除,而且在充分利用扫描剂量的同时,可以根据临床需要自由选择螺距;重建层厚与扫描螺距不相关.

New reconstruction approach overcoming cone beam artifact on multi-slice

The introduction of multi-slice CT (MSCT) was a breakthrough with regard to increased scan speed, improved axial resolution and better utilization of the tube output. However, the spiral CT reconstruction approach was direct affect imaging quality. The feature of single spiral,4 slice and 16 slices CT reconstruction was introduced. Since cone beam artifact, the CT systems with 8 or more slices, the cone-beam geometry caused severe artefacts if not corrected for by a so-called cone-correction. With the adaptive multiple plane reconstruction AMPR in SOMATOM Sensation 16, cone beam artifacts were effectively suppressed, while new spiral concept were created: free selection of spiral pitch according to the clinical needs of an examination, slice width independent of the pitch;full dose utilization at all pitch values.